1. Field of the Invention
The present invention relates to a card connector designed for the connection between an electronic apparatus, such as digital cameras, mobile telephones or the like, and an IC card, more particularly, to a contacting structure of the card connector whose contact terminal structure for the electrical contact with the IC card is improved.
2. Description of the Related Art
For electrical apparatuses such as digital cameras, mobile telephones or the like, it is becoming commonplace to extend various functions thereof by incorporating an IC card containing the built-in CPU and a memory IC.
The card connector is designed for permitting free insertion for loading and free removal for unloading of the IC card and is provided with a plurality of contact terminals, which are arranged within a housing for obtaining the contacts with a plurality of external contacts (hereinafter referred to as “pads”) provided either on the surface or the back of the IC card, so that the IC card can be connected electrically with various signal processing circuits or the power source circuit on the side of the electronic apparatus.
Conventionally, it has been a common practice that the IC card to be loaded into the conventional card connector is provided with a relatively small number of pads, such as 8 pads, especially in the cases of those IC cards which are provided with the controller such as the CPU.
In the other conventional case, the card identification (detection) switch for confirming that the IC card is securely loaded into the card connector is provided at the farthest end of the card connector separately from the contact terminals to be connected with the pads of the IC card (Example: Japanese Patent Application Laid-Open No. 2001-143788).
In recent years, greater compactness and greater functional advance of electronic apparatuses, such as digital cameras and mobile telephones, have been pursued and realized. On the other hand, however, as the performance of electronic apparatuses advances, there has occurred the need for IC cards having larger storage capacity, as experienced in the case of the IC cards for processing image data, such as the XD picture card (TM) and the like. This has resulted in an increase in the size of the IC card itself. Since such a tendency concerning the IC card is a drawback to the pursuit of greater compactness of the electronic apparatus, it is becoming increasingly common to incorporate the controller such as the CPU, which has conventionally been incorporated into the IC card, into the electronic apparatus. Therefore, it has become a common practice to use the IC card provided only with the memory function to reduce the size thereof. As a result, it has become necessary to more than double the number of pads on the IC card, since the pads are necessary for the exchange of the data with the electronic apparatus. Such need has given rise to further need for reducing the pitch (to ½ or less of the conventional pitch) for the arrangement of the contact terminals, as well as the need for reducing the size (width, length, etc.) of the contact terminals themselves.
Such reduction in the pitch of the arrangement and the size of the contact terminal can cause the possible disagreement between the pads of the IC card and the contacts of the contact terminals, the fall of the impact resistance of each contact terminal itself and the fall of the reliability on the electrical contact between each contact terminal and each pad of the IC card. In making the connection with the power source circuit, it is especially important to prevent the instantaneous interruption of the power supply resulting from the vibration and the impact.
As a means for ensuring the electrical contact between each pad of the IC cards and each contact terminal when the vibration and the impact have been generated, a method characterized by dividing the contact portion at the front end of the contact terminal into two parts has been proposed (Refer to Japanese Patent Application Laid-Open No. 2002-100440). However, such attempt is not desirable due to the reasons that dividing the contact portion of the contact terminal into two parts will cause the increase in the time and the cost required for manufacturing because of the fact that the pitch of the arrangement and the sizes of the contact terminals have already been reduced substantially compared with the conventional ones.
Besides, in the case where the card identification switch is provided on the farthest end of the card connector separately from a plurality of the contact terminals arranged in parallel with one another, such composition tends not only to make the connector structure complex but also to increase the number of the parts due to the reason such that the contact terminals for the connection with the printed circuit board of the card identification switch needs to be provided.
In consideration of the problems discussed above, the object of the present invention is to provide a contacting structure of the card connector improved in compactness and simplicity, as well as to provide the card connector with a higher contact reliability and a higher impact resistance.